It's easy to imagine that what you eat has little bearing on your strength, balance and coordination. However you'd be mistaken to believe this. There are a number of ways in which your diet affects strength and the nervous system, which controls balance and coordination. These are listed below.
- Your muscles require a regular source of protein to repair and adapt to training.
- Your muscles and liver require enough carbohydrate in order to avoid utilising muscle tissue as a form of energy.
- Your nervous system requires adequate electrolytes such as salt in order to work at its best and avoid cramps.
- In the long term your bones need to remain strong to anchor your muscles and avoid osteoporosis (brittle bone disease). Calcium status is important here.
The proof that your strength, balance and coordination depend on your diet comes from those with diets deficient in certain nutrients. For these people, some nutrients are clearly critical for their performance level. An example would be an athlete doing an endurance event on a hot day. There will be large losses of electrolytes such as salt, magnesium and calcium in the sweat. As a result cramping, loss of strength, balance and coordination all occur.
Why you need protein to improve strength.
Your muscles are made up from muscle fibres, which are in fact cells that contain a large amount of two proteins called actin and myosin. To keep your muscles functioning well, you need a daily supply of protein in your diet. This protein is broken down into amino acids in the gut, that are then absorbed. Some of these amino acids are incorporated into the proteins actin and myosin that enable your muscles to function.
If you exercise a lot then you need more protein in your diet. One of the main reasons you need more protein supply is that actin and myosin in the muscles are broken down when you exercise. This muscle breakdown occurs not just during weight training, but also when you do endurance exercise. During weight training, or other exercises that put a lot of strain on muscles, the fibres get damaged. The muscle then repairs itself, creating more and stronger fibres than before. During endurance exercise, fibres are damaged and additionally muscle protein may be used as a fuel. So, for both weight training and endurance exercise there is a greater requirement for protein in the diet.
What type of protein should I eat?
Most amino acids can be converted into other types of amino acid in the liver. However a few are not, and these are known as essential amino acids. You need to have plenty of these in the proteins that you eat to ensure you can build your muscles. Foods contain differing amounts of the essential amino acids. Some that contain good amounts of all of them are listed below.
- Meat, fish, eggs and cheese are all great sources of essential amino acids.
- The best vegetarian sources are quinoa and soya beans, closely followed by oats. Nuts and seeds are also reasonable sources.
- Protein powders mostly contain whey or soya protein. Whey is the liquid formed when milk is curdled. It, like soya contains a good amount of all the essential amino acids.
Basically if you eat enough of protein containing foods you will have the essential amino acids you need to build and repair muscle. The adverts you see for products or foods implying superior protein nutrition are often pretty meaningless. Just sit down to a meal containing good protein sources and your amino acid needs will be fulfilled.
How much protein should I eat?
If you exercise hard then you will need more protein in your diet. In terms of grams required it is often quoted that 0.8g are required for each 1kg of your bodyweight. This of course assumes that you are in the healthy range of bodyweight and that you are not exercising very much. For people who do plenty of exercise or those wanting to lose weight it is better to eat more calories in the form of protein. The harder and longer you exercise for, the more protein you are likely to require, and an amount between 1.2-1.8g of protein per kg of bodyweight is probably more realistic. For somebody weighing in at 68kg or (10st 10lb) and exercising hard for around 10 hours per week this equates to around 104g of protein per day. For somebody of the same weight who is not exercising very much, but wants to lose weight they should probably consume about 68g of protein per day (1 g per kg bodyweight).
There has been a tendency in the last 20-30 years to over emphasize the importance of carbohydrate in the diet of athletes, and this has led to athletes who are weaker than they should be and who don't recover from intense efforts as quickly as they should. Carbohydrates such as pasta, potatoes, rice and bread should be used principally to keep your stores of glycogen topped up, but not eaten at the expense of adequate protein and fat.
Why it's important to eat after endurance training.
If you want to maintain strength then you need to ensure that your body does not start using protein from the muscles as a fuel source. This occurs anytime when the glycogen stores in your muscle and liver are low. Glycogen remember, is broken down into the high octane energy fuel called glucose. Long, vigorous exercise sessions or starvation deplete glycogen levels to such an extent that the body is forced to use other energy sources to provide glucose.
While fat reserves can be used to fuel many processes in the body it is not possible to use it for everything. The brain and red blood cells can obtain energy only from glucose. Now fat cannot be turned into glucose by the human body. Protein can if the amino acids it contains are converted by the liver. Carbohydrates require little or no conversion as they are absorbed as glucose and fructose. It is therefore best to consume carbohydrates during and after long and intense exercise sessions to ensure your glycogen levels are preserved. As a guide, if you exercise for over 30 minutes at a high intensity or about 60 minutes at a moderate intensity you will be needing to consume extra carbohydrate. This is best consumed within the first hour after finishing exercise as this is when your body will be primed to convert glucose in the blood into glycogen in the liver and muscles.
To decide whether it is neccessary to eat during a training session you should ask yourself how you feel during the session. If you are getting light headed, dreaming about food or feeling a whole body fatigue then you are probably low on blood sugar and should be consuming more carbohydrate. Typically, the fitter you are, the longer you can exercise without taking on carbohydrate sources such as sports drinks, gels or bars. For most people it is worth consuming carbohydrate sources during exercise if it lasts longer than 60-90 minutes. Many people consume sports drinks during exercise session of less than one hour. This is not necessary unless you are exercising under hot conditions, where the need for electrolytes and hydration are great. Indoor cycling or rowing can easily fall into this category. Note that carbohydrate is not as important here as the salts in the sports drink.
Avoiding muscle cramps.
Muscle cramping is caused by overexcited nerves in the muscles. This can result from a variety of causes:
- Injury, such as a broken bone where the muscles may contract to keep a neighbouring joint stable.
- Lack of conditioning for a particular activity. Both stiffness and cramps can result from this.
- Muscle shortening during rest. e.g. sleeping with pointed toes may shorten your calf muscle causing a nightime cramp. This can occur as you roll over during sleep.
- Some drugs and medical conditions can cause cramps. A notable culprit being the statin drugs, used for cholesterol reduction.
- Lack of sodium is a major cause of cramps. Low sodium status can result from sodium lost in sweat during warm weather or vigorous exercise. Sodium is also excreted in urine as a result of taking diuretic drugs, leading to increased likelihood of cramps.
- Low calcium, magnesium or potassium status. For athletes, it is most likely that loss of sodium is the culprit for cramps, as sweat reduces sodium levels faster than those of other minerals. However calcium is one mineral that can be significantly depleted by profuse sweating. A lack of calcium and to a lesser extent, magnesium and potassium in the muscle can cause cramping.
- Dehydration or hyperhydration. If too much, or too little water is present in the muscle fibres, then they do not work properly and cramp can result. Water follows electrolytes into different compartments as it is always trying to move from weaker solutions to stronger solutions. An effect called osmosis. As such, you can deplete sodium or calcium from the interstitial fluid between the muscle fibres by profuse sweating. When this occurs water will move into the muscle fibres from the more dilute interstitial fluid. This dilutes calcium concentration in the muscle fibres leading to their continued contraction and therefore cramp.
Short term treatment.
To treat muscle cramps it is best to stretch the affected muscle gently. A gentle massage of the muscle towards the heart and warming the effected area in a bath or with warm towels should also help.
Longer term treatment.
Make sure you are well hydrated and stretch regularly. Use fluid replacement drinks that contain adequate amounts of salt if you are likely to sweat a lot. This is especially important if you are about to encounter conditions that are warmer than normal or exercise routines that are longer or harder than you are used to. It is worth eating foods that contain a reasonable amount of calcium, magnesium and potassium also.
Keeping bones strong.
Sweat contains calcium and it is possible to lose as much calcium in sweat during 4 hours of exercise as you absorb from your diet in a whole day. A calcium deficit may not lead to problems in the short term, but over a longer period of time it can reduce the amount of calcium in the body available for repairing and building bones. For athletes who exercise for prolonged periods over a number of years, this can contribute to osteoporosis (brittle bones). As a result it is wise to include plenty of calcium sources in your diet such as milk, cheese, yoghurt, soya based products and fish such as sardines. This is especially the case for women who exercise a lot and produce plenty of sweat.